System for handling granular material and the like



P. DIEBOLD March 1, 1960 SYSTEM FOR HANDLING GRANULAR MATERIAL AND THE LIKE 2 Sheets-Sheet 1 Filed Feb. 19, 1958 March 1, 1960 P. DIEBOLD 2,926,961

SYSTEM FOR HANDLING GRANULAR MATERIAL AND Ti-IE LIKE Filed Feb. 19, 1958 2 Sheets-Sheet 2 SYSTEM FOR HANDLING GRANULAR MATERIAL AND THE LIKE Pierre Diebold, Nancy, France Application February 19, 1958-, Serial No. 716,200

4 Claims. (Cl. 302-42) vfor granular materials discharge or collector apertures are provided which are generally mounted in one or more fixed positions at the base of the silo or the like. The granular material is fed by gravity towards and into the collector aperture only to the extent that such material is lying within the surface of an inverted cone having its apex at the aperture and a cone angle equal to the natural slope angle of the material.

Hence, it is usual to construct silos with funnel-shaped bases Such construction however involves a necessary loss of floor space. Moreover for a given storage capacity such silos have to be constructed to; a relatively great elevation with a consequent increase in construction costs.

It has been proposed to store grain in flat-bottomed silos and collect the grainby means of suction nozzles connected to a source of high vacuum. The pipes are extended out of the silo to dump the grain where desired. The suction nozzles have to be :moved over the storage area by operators who have to work in a dustladen unsanitary atmosphere. Moreover such installa: tions are complicated and have not gained wide acceptance.

In another type of installation the bottom of the silo is in the form of an upwardly open dihedral angle and an elongated trenchor trough-like excavation or pit is provided under the edge of the dihedral. A conveyer, usually of theendless belt or chain type, is arranged in the excavation and the top of the excavation is sealed as by a plurality of sliding doors displaceable manually or mechanically in a horizontal plane in a direction at right angles to the longitudinal extent of the excavation. Thus the operation of such doors one at a time will provide a single aperture into the excavation and the doors can be slid open one after the other to discharge the grain. While such a discharge system has certain ad vantages, the operation of the sliding doors is complicated and they are liable to jamming at frequent intervals owing to the high loads applied to them normally to their direction of movement. The mechanical conveyer means in the central pit are not readily accessible. ther, such a system is not practically applicable for use with storage areas having flat surfaces of comparatively large area.

Objects of this invention are to provide handling means for materials of the type described which will be com. paratively easy and inexpensive to construct, operate and maintain while possessing increased efliciency over any of the means heretofore used; toprovide such handling means which will be usable both with funnel-shaped storage areas such as silos, and with flat storage areas of large size; to provide such handling'means in the form of conduit-like structure that can be placed in a re uired Fur- 2,926,961 Patented Mar. 1, 1 960 location on the bottom of a storage enclosure prior to the storage of material in said enclosure and which will subsequently operate in an efiicient manner after the enclosure has been filled with material to substantial depths; thus, such a conduit may have a length of feet and more and will operate efiicientl'y when buried under a depth of 15 to 20 feet and more of grain. Other objects of the invention are to provide fora mechanical displacement of the discharge outlet at the bottom of a silo or similar storage enclosure opening into a conveyer means for the discharged material; to provide such a system which will only require a small amount of mechanical power for shifting said outlet and will not be liable to be put out of order due to jamming under the load of stored material acting thereon or other reasons. Further objects will appear as the disclosure proceeds.

In its main aspect the invention provides a system for handling granular and equivalent materials in a stor age area, which comprises means defining a conduit having a longitudinal opening along at least one of its walls, said conduitbeing adapted to be arranged on said area with its open wall in contact with the stored material, a band or strip-like element slidably sealing said open wall of the conduit means and formed with at least one aperture in it, means for displacing said element longitudinally along said wall of the conduit in the plane of said element so as to expose said aperture(s) to different portions of the stored material, and conveyer means within said conduit for conveying material entering through said aperture(s) along the length of the conduit means Preferably the conveyer means within the conduit are provided by an air blast. The slidable element can be one leaf of an endless belt guided between flanges of the conduit wall, and the relative vacuum obtaining in the conduit when an air blast is used as the materialconveying means, will act to apply said one leaf of the belt into substantial sealing engagement with said guide flanges. Since during the displacement of the element orendless band, the surface area of the moving element exposed to the stored material remains constant, the

. power requirement remains uniformly low. While the open wall of the conduit means in which the slidable apertured sealing element is arranged may be a top wall, or one or both side walls of a box-shaped conduit structure, according to a preferred form of the invention such a-box-shaped conduit structure is supported in spaced relationship from the surface of the storage area on which it. is placed and the slidable sealing element is provided in the bottom wall of the structure. The abovementioned vacuum within the conduit then serves to draw in the material upwards through the aperture in said bottom element, and does not exert any load due to gravity upon the element so that the power required to displace it is further reduced.

According to another form of the invention the condut defining means may comprise a trench-like excavation, pit or trough formed in the storage area, the apertured slidable sealing element being provided in the open top of said excavation.

The invention will be clearly understood from the ensuing description thereof wherein a few exemplary embodiments are described for purposes of illustration but not of limitation and with reference to the accompanying drawings, wherein:

Fig. l is a transverse cross sectional view of a grain discharge or collector conduit assembly according to the invention, positioned within a longitudinal pit formed in the bottom of a silo;

Fig. 2 is a plan view on a smaller scale of one end of the conduit; I e e v Fig'. 3 is a longitudinal section on line III+III of Fig. 2;

3 Fig. 4is a sectional :view of a modified form of the collector assembly shown in Fig. 1; l. t I

Fig. 5 is a transverse section of a collector conduit assembly according to the invention adapted to be positioned at the foot of the sidewalls of a silo; Fig. 6 is a sectional view of a further modification; Fig. 7 is a plan view of a silo equipped witha collector system of the type shown iniFig.'4; i

Fig. 8 is a plan view of'a silo equipped with asetof rectilinear collector conduits according to the invention.

Referring to Fig; 1, there is shown a silo l-inthe bottom of which a trench or pit 2' is excavated. Fig. 1 illustrates .a cross section of 'the'pit the latter extending throughout the full length of the silo'and prefer-ably along a middle line of the'storage area. i I

A metallic conduit 3 'ofrectangular cross-section is placed on the. bottom of thetrench 2 and extends .the length of it. The conduit is open at its top having :two inwardly-directed horizontal 'topflange's .4'and S' and-a band 6 of semisflexible material has its side edgessupported on said flanges. Additional flanges 7"and fispaced above the flanges 4 and 5 overlie the band 6 and serve to guide it. The band 6 is supported in the'conduit upon spaced rollers 9 freely rotatable on journals 10. t

The conduit 3 with the band ,6 define a continuous substantially sealed casing or passageway through which the granular material, e;g. grain, can be conveniently moved for example by -means of pneumatic conveyor equipment. 1Subatmospheric pressure created by the pneumatic means within the conduit applies the band into sealing engagement against theflanges 4 and 5 thereby providing for axsatisfactory operation of said pneumatic means. The grain stored in :the silo is guided :towards the top of the conduit assembly by means of .theusual inclines .10 and 11 and isadapted to enter the conduifby way of an aperture 12 formed in .the band 6, and is then taken up .byafstrongrairblast rge'uerated through the compartment 13 of thec'onduit 3.. 1A fur her'icompare ment ll l serves simultaneously to admit fresh air and is separated from compartment 13 by a partition 15'. The partition is cut off at the end'of' the conduit, see Fig. 3, so as to provide communication between both compartments. Referring to Fig. 3 it will be noticed that the fresh air is discharged in the direction of the arrow f1 and carries the grain'with has indicated by the arrow f2, around the end ofthe partition 15, since theend of the conduit is sealed by an end-wall 16.

By gradually displacing theband 6 through its guide- Ways 7,-8 the discharge aperture 12 :can bewshifted-as indicated bysthe. arrow f3. Thus at thestart'of n discharge operation aperture 12 maybe positioned at the end of the conduit near -to the verticalwall 17 of the silo. After all the grain'positioned above the aperture 12 has been withdrawn so that only heaps of grainsu'ch as 18, 19 and- 20 remain on either side of the trench and near the end wall 17 respectively, said heaps slanting with the natural slope angle of the grain, the strip6 is shifted in the direction 3. Asuitable uniform rate of displacement may be. selected to permit all the grain situated in the areas 18, 19 and 20 'to be gradually discharged as the opening 12 is advanced the length of the s10. r r

In this way a large proportion of the granular, material stored in large size silos canzbe conveniently discharged by mechanical means. The relative amount of material thus discharged canof course be-increased by providing more than one assembly similar to that shown in Fig. .1, arranged parallel to one' another and suitably spaced across the base of the silo. At the end of such an operation there will on ytemain small amounts of grain in the.

side areas 18.and 1 9 and these can easily be-taken care of manually or otherwise after the described operation has been completed.

In the construction described with reference to 1 the band dis-in-the tormotan endless belt audits trained guided in guideways 23 along the-opposite sideof-the conduit being supported onrollers 22 similar to the rollers 9 supporting the leaf 6. It will be observed that since the band is displaced along a direction lying in its own plane, the power required to drive the drum 21 is relatively very low. 7

Standards 24 secured e;g. welded to the sides of the conduit and projecting upwards-therefrom are provided for supporting the inclines '11.

Referring to Fig. 4 the conduit 3 there shown is supported on the bottom'of the silo and its two side faces are longitudinally slotted the length ofthe conduit and receive the bands 6a and 6b, which are respectively formed with apertures 12 and 12b. The compartment 14 in this case is subdivided into an upper compartment 14a and a lower compartment 145. The top of the conduit in this construction is scaled and is covered the full length of the conduit with a roof-like cover 25 which serves to direct the grain towards either side er the conduit. Thetriangular space 26 defined between the top of' the conduit and the cover 25 may be used for housing equipment for any of various purposes, as for ventilation, protection against pests, and/or other services;

As shown in Fig. 5 the collector conduit of the invention may be positioned in a lower'corner of a silo. In such case there may be provided a single band 6 which is led all the way round the storage area so that acompl'ete'discharge of'all the stored grain is made possible al'ong'the margins of the area. In such case a construction similar to Fig. 5 employing a band'6 in a vertical plane ispreferably used.

'-Fig. 6 illustrates a form of embodiment that is especially desirablein many circumstances and wherein the conduit shown in -Fig; l is'ar'rangd in inverted condition and is supported onilegs 27. The belt includes a lower operative lca'f extending along the bottom "of the conduit ahd formed with an opening '12 while the upper return loop is guided along the top inner wall of the conduit. The granular material flows into the space underneath theconduit, rises'up into compartment 13 under the pressure exerted by the body of material above it aided by the suction created in the conduitand is discharged by the air-blast. {The vertical clearance h'beneath the conduit is'so predetermined that the grain will readily flow under the conduit and will be efficiently drawn into it as described. 1

T-he main advantage of this embodiment lies in the fact "hat the band 6 does not have to 'sustain'the' high pres reofthe stored material and will thercfore-not tend to'be'com'e' distorted orsag b'etwe'en adjacent suppor'ting rollers. Moreover the band is not strongly applied against the guide flanges 4 and 5. Hence the mechanical powerrequired for imparting longitudinal displacement to" the band isfurther reduced with respect to the embodiinent shown in the precedingly described-figures especially Fig. 1, in which 'a substan'tifl retarding action was applied by the grain 'tothe band.

Figs. Ta nd '8 illustrate exemplary lay-out schemes for the conduits over the storage area with the object of minimizing the residual heaps ofgrainnotamenable to treatmentby the conduits. -The system fragme'ntarily illustrated Fig. 7 utiliaes a single conduit having side 'a 'Jt'e-rture's of the type shown in Figs. 4 and '5 described .therto from different parts of the storage area. r

invention 'is'n'o't lhni'tedito'fthe term of embodiment described and illustrated herein by way of example. Thus, instead of using a band 6 or bands of semi-rigid material, a relatively rigid strip may be used in cases where it is found convenient to impart to such a strip longitudinal displacements along a direction lying in the plane of the strip so as to shift an aperture or apertures formed in the strip in a manner similar to that described.

Moreover, while the material moving means provided within the conduit were described as comprising pneumatic conveyer means in the preferred form of the invention, other types of conveying equipment may be employed including hydraulic conveyers, belts conveyers, screw conveyers, scraper arms, or the like. Such conveyer means would be arranged beneath the displaceable band or strip 6 in Fig. 1 for example.

According to another modification, a longitudinally extending trench or pit formed in the bottom of the storage area may serve to provide the bottom and side walls of a collector conduit according to the invention, with a band such as 6 being arranged for displacement in guideways provided along the tops of the sides of said pit or trench.

While the conduits were described as being generally stationary during a collecting operation, means may be provided for imparting to a conduit of the kind described herein a scanning displacement over the storage area, especially during the later or end stages of a collecting operation. Thus, conduits especially of the types shown in Figs. 4, 5 and 6 herein which have collecting apertures arranged in the sides or bottom thereof, can consist of or include flexible or pivoted sections to provide for such displacement. Similarly flexible hose sections may if desired be connected to the collector aperture or apertures such as 12.

Collector systems according to the invention are not necessarily restricted in their use to granular materials such as grain although the invention is of particular advantage in that connection. The invention may be applied to the handling, e.g. discharge, collection, spreading and similar operations, of any materials of the kinds that are usually handled by first placing the materials in suspension in a stream of fluid, e.g. in malting plants, as for delivering the barley to and from the soaking troughs, as well as in handling ores in mining operations, in earthwork, and other engineering plants.

What I claim is:

1. A system for handling flowable solid material in a storage area, which system comprises means defining a conduit having a longitudinal opening along at least one of its walls exposable to material handled in said area, an elongated strip-like element supported within said conduit means in slidable sealing engagement with said open wall, at least one aperture formed in said element, means for displacing said element longitudinally of said wall to expose said aperture to diiferent portions of the handled material, and conveyer means in said conduit for conveying material entering through said aperture along the length of the conduit means, said element comprising one leaf of an endless belt element, and means within said conduit means for supporting the opposite leaf of said endless element adjacent a side of said conduit means opposite said open side.

2. A system for handling flowable solid material in a storage area, said system comprising means defining a conduit having a longitudinal opening along at least one of its walls exposable to material handled in said area, one leaf of an endless belt element supported within said conduit means in longitudinally slidable sealing engagement with longitudinal edges of said opening, at least one aperture formed in said element, means for displacing said element longitudinally of said wall to expose said aperture to different portions of the handled material, conveyor means in said conduit for conveying material passing through said aperture along the length of the conduit means, and means within said conduit means for supporting the opposite leaf of said endless belt element adjacent a side of said conduit means opposite said open side.

3. A system for handling flowable solid material in a storage area, which system comprises means defining a conduit having a longitudinal opening along at least one of its walls exposable to material handled in said area, an elongated strip-like element supported within said conduit means in longitudinally slidable sealing engagement with longitudinal edges of said opening, at least one aperture formed in said element, means for displacing said element longitudinally of said wall to expose said aperture to different portions of the handled material, conveyor means in said conduit for conveying material passing through said aperture along the length of the conduit means, a longitudinal partition in said conduit defining two separate compartments within the conduit communicating at the end of said conduit,

and means providing air blasts flowing through said channels in opposite direction.

4. A system for handling flowable solid material in a storage area, which system comprises a box-like structure having longitudinal openings along both opposite side walls thereof defining a conduit exposable to material handled in said area, endless belt rneans providing an elongated strip-like element supported within said conduit means in longitudinally slidable sealing engagement with longitudinal edges of said openings, at least one aperture formed in said element, means for displacing said element longitudinally of said wall to ex pose said aperture to different portions of the handled material, and conveyor means in said conduit for conveying material passing through said aperture along the length of the conduit means.

References Cited in the file of this patent UNITED STATES PATENTS 1,207,794 Reddy Dec. 12, 1916 2,310,620 Dye Feb. 9, 1943 2,650,726 Aller Sept. 1, 1953 FOREIGN PATENTS 463,953 Germany Oct. 27, 1925 

